Safe end flue



C. S. COLEMAN. SAFE END FLUE. APPLICATION FILED SEPT. 9, {918.

Patented May 11, 1920.

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nnrrnn snares PATENT orrion CHARLES S. COLEMAN, OF LOS ANGELES, CALIFORNIA, ASSIGNOR TO THE COLEMAN BOILER APPLIANCE COMPANY, OF LOS ANGELES, CALIFORNIA, A CORPORATION OF DELAWARE.

SAFE END FLUE.

Application filed September 9, 1918.

T0 cZZ whom it may concern:

Be it known that 1, CHARLES S. COLEMAN, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented new and useful Improvements in Safe End Flues, of which the following is a specification.

This invention relates to a flue-end for connecting the terminals of fines to the end plates of boilers, particularly in boilers of the fire-tube type employed in locomotive construction.

One of the most troublesome elements of locomotive boiler construction is that of the juncture of the fiues with the boiler end plate at the fire box end of the boiler, because of the difliculty of eflecting a tight joint which will endure the stress of vibration, expansion under heat, and contraction when cooling, and also withstand the destructive and weakening effect of corrosion. It is a common occurrence for new locomotive boilers to leak after a few months service. Minor leakage is not considered sufficient cause to warrant withdrawing the engine from service for the repair of a few flue connections, and as a consequence the engine is kept in service and operated at an increased cost and at a lowered efliciency because the use of additional fuel is necessary to maintain steam pressure, thus resulting in increased fuel consumption relative to tonnage hauled, and less tonnage and mileage are obtained from a given amount of fuel than would-be the case if the flue joints were tight. Furthermore, much time is lost in repairing the flue joints, it not being infrequent for a locomotive to be out of operation one-tenth of its time on account of making flue repairs.

It is the object of this invention to provide a flue-end of such character as to reduce leakage at the juncture of the flue to the boiler end plate to a minimum and consequently decrease the loss of time, waste of fuel, and expense incident to the maintenance of boilers in which the ordinary well known types of flue connections are employed.

A. further object is to provide a construction whereby a relatively soft metal flueend may be interposed between a flue terminal and a boiler end plate, and aflixed to each to effect a substantial and durable con nection between the flue and end plate, and

Specification of Letters Fatent.

Serial No. 253,179.

which construction will permit the use of a copper or brass flue-end on a steel flue and thereby obviate corrosion and minimize fracture of the flue-end because of the non-corrosive character of brass or copper and the greater malleable-properties thereof relative to steel flue-ends. Other objects will appear hereinafter.

The invention is illustrated in the accompanying drawings; in which; Figure l is aview illustrating the flue-end 1n longitudinal section and showing the manner of attaching it to the flue terminal and to the boiler end plate;

Fig. 2 is an enlarged detail in section of the-flueend and its joints.

More specifically, 4: indicates a boiler end plate, the outer and inner faces of which are designated a and b respectively. The plate is formed with a'flue-end receiving opening having a tapered wall 5 which tapers inwardly from the outer face a of the plate toward the inner face 6. A counter-bore (3 may be providedon the outer margin of the tapered wall 5 forming an annular countersunk shoulder 7 on the outer face of the sheet.

8 indicates a boiler flue which terminates at c and which extends over the end of a tubular flue-end member 9 adapted to be interposed between the end of the flue and the boiler end plate. Theflue-end 9 is made of a metal more malleable and soft and having greater heat conducting qualities than the metal (usually steel) of which the flue and end plate are formed, copper, or brass being preferably employed because of their lack of brittleness and non-corrosiveness.

The outside diameter of the flue-end is greater than the diameter of the inner or reduced end of the opening in the end plate, and the outer end of the flue-end is reduced in outside diameter, as indicated at 10, so as to pass through the opening and to provide a shoulder 11 to seat on the inner face of the end plate around the margin of the opening. This reduced end of the flue-end is inserted in the opening and expanded to conform to the tapered wall 5 and its terminus is beaded over the shoulder 7 into the ccunterbore 6 so as to dispose the inner face of the bead and the edge thereof in a recess to protect it against direct action of flames and also prevent deposits accumlating thereunder.

Patented May 11, 1920. v

The inner end of the flue-end is of such outside diameter that the end of the flue on being expanded by heat may be slipped thereover and on cooling shrink into tight engagement with the exterior of the flueend.

As a means for insuring a tight and permanent joint between the steel flue and the soft metal of the flue-end, an annular channel 12 is formed in the flue end at the terminus of the flue, which channel may be cut by a suitable tool or may be formed by a welding torch or the like. An annulus of metal 13 of suitable character is then run into the channel 12 by welding which on being welded to the end of the flue and to the walls of the channel in the flueend affords a substantial and non-leakable joint.

The tubular flue-end is preferably formed with an outside diameter substantially the same as that of the interior diameter of the flue, and as before stated, slightly larger than the inner diameter of the flue-end receiving opening in the boiler end plate, so as to obviate machine work in reducing the ends thereof. Furthermore by forming it of such diameter, a sleeve 14, of steel, may be shrunk over the flue-end to extend between the flue terminal and the inner face of the end plate without enlarging the outside diameter of the flue-end to a point greater than that of the flue. This sleeve provides a reinforcement for the flue-end, and is joined to the end of the flue by the weld annulus 13 to form a more substantial connection between the flue and the flue-end.

I claim:

1. A flue-end comprising the combination with a flue of a soft-metal tubular member inserted at one end into the flue, a reinforcing hard-metal sleeve encircling said member and spaced from the end of the flue forming an annular channel, said member formed with a peripheral groove in continuation of said channel, and a weld annulus disposed in said channel and groove joining the adjacent ends of the tube and sleeve.

2. The combination of a boiler end-plate having a flue-end receiving opening therein, a softmetal flue-end having an outside diameter greater than that of the opening and formed with a reduced end insertible in. said opening and providing a shoulder to seat on the inner face of the end-plate, a reinforcing sleeve encircling said flue-end and abutting against the end-plate, said flueend projecting beyond the opposite end of the sleeve and having an annular channel contiguous to the sleeve end, and a weld annulus in said channel a'ffixing the sleeve to the flue-end.

CHARLES S. COLEMAN. 

